All had set records and broken barriers that seemed to qualify them for the sort of ''right stuff'' celebrated in book and film these days.

Yet it was their first names - Irene, Susan, and Colleen - that made them part of an even more exclusive ''brethren'': that small but growing group of women assuming previously all-male roles in military service, and quite willing to fight for their country.

After an unsuccessful 10-year effort, supporters of the Equal Rights Amendment (ERA) are once again beginning their battle on Capitol Hill, responding to questions and criticism about women being drafted and sent into combat. United States troops in Lebanon and Grenada today make the subject particularly relevant, everyone agrees.

In the decade since affirmative votes in House and Senate launched the first fight to secure an ERA, women have made significant strides in the US armed services, despite the ERA's initial defeat. Their ranks have increased severalfold, they are graduating from the service academies, and many more jobs have been opened to them, including some closely related to combat. And the public - according to opinion polls - now is more willing to accept women as part of any military conscription.

Still, military women express frustration over remaining restrictions and career limitations based on their gender. And feminists are challenging the notion that women ought not to be in combat roles, since the ''new battlefield'' in any major conflict will know no front lines and many women will be in the thick of it in any case.

Within the military establishment, there is growing acceptance of the contribution made by the 190,000 women in uniform.

Introducing the panel of servicewomen at last week's congressional hearing, Air Force Lt. Gen. Edgar A. Chavarrie said: ''The services are justifiably proud of these officers. Women are a vital element within our all-volunteer force.'' And there was no doubting the enthusiasm or commitment of the women who testified.

''We are here to stay and we are dedicated,'' said Lt. (jg) Susan K. Donner, who graduated from the US Coast Guard Academy three years ago and now commands a crew of 13 men aboard the Coast Guard cutter Cape Henlopen.

''Generally, I think the attitudes among men in the Coast Guard are positive toward women,'' said Lieutenant Donner, whose task is to chase drug smugglers and perform search-and-rescue operations out of Woods Hole, Mass. ''They see that we can do the job in a professional manner.''

The Coast Guard, which reports to the US Department of Transportation rather than the Defense Department, in recent years has opened all jobs to women, including command at sea. In wartime, however, the Coast Guard would come under the US Navy, and current rules prohibiting women from serving on combat vessels would apply.

Such rules in the Army, Air Force, Navy, and Marine Corps are based on congressional restrictions against women in combat and the perceived physical inability of women to perform some jobs. But this is changing.

In October, the Army reversed an earlier decision and reopened to women 13 job categories that had been closed last year because they might involve direct combat. These include fire-control-systems repair and nuclear, chemical, and biological warfare specialist. Responding to pressures from women in uniform as well as women's rights activists, the Army also said it would increase its recruiting goals for women and administer a less stringent physical-strength test that would in effect make more jobs available to women.

Ironically, recruiting restrictions can have the effect of making women better qualified than men for the highly complex and technical military jobs increasingly part of all preparations for battle. For example, women who want to enlist in the Army or Navy must have a high school diploma. This is not required of men. Women marine recruits need better scores than men on the Armed Forces Qualification Test to be accepted in the corps.

Women in service lose more time for medical reasons (including pregnancy) than men. But when unauthorized absences, time in the brig, and other disciplinary problems are included, men lose more work time than women, according to a Navy study.

And many women in uniform bristle at the suggestion that they cannot stand up to the rigors of training for - or fighting - war.

''We have plenty of pressure and stress right now,'' said Lt. Colleen Nevius, the first woman to become a US Navy test pilot. ''Of the women I've seen come through, I have no question about their abilities, their aggressiveness, their strength . . . anything.''

The opening up of new jobs and the changing nature of conventional warfare - more fluid battlefields with long-range weapons and attacks against rear echelons - are likely to see more women involved in combat, regardless of congressional restrictions. And those who testified before the House Subcommittee on Civil and Constitutional Rights recently were very clear about their preparedness to fight if called upon.

''There's no doubt in my mind that I could do it,'' said Air Force Capt. Irene L. Graf, command pilot of a KC-135 tanker. ''I'm not second string at all. I pull alert [duty] every third week just like my male counterparts, and I wear a combat-readiness ribbon.''

ERA advocates are thus focusing on the career and economic limitations that come with existing restrictions on women in the armed forces.

''Exclusion from the benefits of military service means lost opportunities for college scholarships, veterans' benefits, veterans' preference in government employment, veterans' insurance, and loan programs,'' says Carolyn Becraft a former Army officer and director of the National Center on Women and the Military, a project of the Women's Equity Action League. ''And (it means) limited access to the revolving door of the military-industrial connection - where the private sector pays well for the defense-related skills of former service members.''